The present invention relates to a filter assembly capable of selectively removing toxic gases and dust floating in and entering a magnetic disk drive, and a magnetic disk drive having such a filter assembly.
It is a common practice with a personal computer or a word processor to use storage implemented as a magnetic disk drive accommodating magnetic disks therein. To meet the increasing demand for greater storage capacity and higher recording density, the spacing between a head and the associated disk must be reduced. However, a reduced spacing between the head and the disk brings about a problem that when dust and toxic gases, i.e., sulfur oxides, nitrogen oxides and chlorides enter the disk drive and deposit on the disks, they erode the disks and cause head crash to occur. To eliminate this problem, it has been customary to provide the disk drive with a filter device made up of a dust filter and a gas filter. For example, a filter device taught in Japanese Utility Model Publication No. 3-37696 consists of a dust filter in the form of filter paper folded in a corrugated configuration, and a gas filter received in a casing and constituted by activated charcoal.
However, the above-described filter device is not satisfactory since the ability thereof to remove dust and toxic gases is not sufficient in relation to materials constituting the individual filters. Particularly, since the ability of the conventional device to remove erosive gases is insufficient, the disks are locally eroded and suffer from microscopic undulations on the surfaces thereof. This results in head crash and, therefore, prevents recording and reproducing characteristics from being effectively maintained, thereby degrading the reliability of a magnetic disk drive.